Re: [boost] [optional] Making optional more debugger friendly

From: Joe Gottman (jgottman_at_[hidden])
Date: 2007-05-22 20:21:49

Jeffrey Faust wrote:
> My only complaint about boost::optional is that it is very difficult to 
> see values in the debugger.  I brought this up in a discussion at 
> BoostCon, and Jeff Garland suggested I submit a patch.
> 
> Well, I have a patch.  The change introduces a new private T* m_value 
> and protected method update_debug() which sets this variable.  The 
> variable is only visible when building debug, and the method is empty in 
> non-debug.  From there, I simply call update_debug() in each public 
> method that changes the storage.
> 
> The final result is that debuggers can see the variable data by looking 
> at opt.m_value.  When not set, the value is null.
> 
> Any thoughts?

If I want to see the result of an optional, I often write code that 
looks like the following:

optional<int> opt;
/// Time passes...
if (opt) {
    const int &i = *opt;

Then I can just watch i.  I do the same thing with iterators, especially 
into sets and maps.

Joe Gottman